Dress inconspicuously. Ensure you are wearing clothes that fit in to the region of the world you are in so you don't look like a foreigner. Also, refrain from overdressing so it doesn't appear that you have a lot of money. Leave expensive and sentimental jewelry at home. Keep your cash hidden as well. Pulling out a wad of bills can tip off would-be thieves.
Pack conservatively. The more you take with you on a trip or vacation, the more you have to look after. If you have a bunch of possessions to look after, it is more likely that you will be ripped off.
Carry only the cash that you intend to spend while in the city. This takes some advance planning. Decide how much you will spend on food and souvenirs while in the city, then leave the rest of your money at your motel. If your room has a safe in it, use it.
Keep an emergency contact list of phone numbers that you could need. These numbers should include your bank, relatives back home and the local consulate for your home country. These numbers will come in handy should you become the victim of a pickpocket or thief. It is also a good idea to keep the phone number of your credit card companies handy.
Make extra copies of all of your documentation. This should include your passport and traveler's checks. It is important not to keep these copies in the same place as the originals. Leave the copies in your motel room, or for better protection, with a relative back at home. Also, bringing an extra passport photo will make replacing your passport easier if you lose it.
Keep your currency separated. This means keeping your traveler's checks, credit cards and money separated from each other. This might make it more confusing to pay for things at local stores, but it will also ensure that you still have some currency to use if any of the others gets stolen.
Buy a money belt and use it while traveling. This will ensure that you can carry keys, wallets, and other valuables around your waist. It isn't a great fashion statement, but it does the trick. If you do not want to wear the money belt, then place your wallet in your front pocket. It is more noticeable when someone tries to steal something from your front pocket than your back pocket.
Stay aware of the people around you. If someone approaches you to ask for directions, stay aware. This is a method that some thieves use to take advantage of tourists. One thief will distract you while another comes out of nowhere and steals something from you. Some thieves try a variation of this trick that involves "accidentally" spilling a drink on tourist. If something seems suspicious, it may be best just to get away from the area and the people who approach you.
Leave your expensive camera at home. Thieves love to get their hands on an expensive looking camera that a tourist sits down for a second. Take an inexpensive camera with you. This can include instant cameras and disposable cameras. The quality may not be as good, but it can save you tons of money in the long run. If you absolutely have to take your expensive camera, make sure to hide it well. Buying something at a local shop and hiding the camera in the shopping bag is an effective way to hide your camera. Make sure not to take your eyes off your bag, though.
Stay in areas that you know are safe. Most places that are intended for tourists are well lit and populated. Wandering around in an unknown town could cause you to stumble into an unsafe area. If you decide that you want to see parts of the city that you aren't sure are safe, talk to a few locals, or even the hotel staff. Never go by just one person's opinion, as they may be leading you somewhere so they can rob you.
